Continuity mistake: Kirk turns his head and displays a stunned look... a full second before the Gorn even starts to disappear. (00:45:47)
Continuity mistake: After the battle ends, Kirk looks up to the exact spot where the Metron will be standing, way before the Metron even materializes. (00:45:53)
Continuity mistake: When Kirk and Spock are chatting in Kirk's quarters, they finish their discussion and as they head out Kirk orders the ship to red alert. Then after the commercial break, they're on the bridge, the Gorn ship is at a dead halt, and Kirk orders the ship to red alert again. With a hostile ship in the vicinity, Kirk, a highly experienced captain, would hardly have taken the ship off red alert.
Tomorrow is Yesterday - S1-E20
Continuity mistake: When Kirk and Sulu enter the records room, they pick the lock. Later when they beam the officer back down, he enters the room without unlocking the door. The room should be locked since they beamed him down in the "past" erasing their having been on Earth and in the records room.
Tomorrow is Yesterday - S1-E20
Continuity mistake: When the plane is coming up to intercept the Enterprise, it's shown flying through thin clouds, yet when inside the cockpit, there are no clouds to be seen.
Continuity mistake: McCoy uses a "masking device" to block out the bridge personnel's heartbeats. When McCoy masks Spock's heartbeat, he holds the microphone, err, masking device over the wrong part of Spock's anatomy. We'd already established that Spock's heart wasn't in the same place as a human.
Continuity mistake: They said that engineering was "B" deck which is deck 2, but engineering is deck 7 which would be "G" deck.
Continuity mistake: In the finale of the fight between Kirk and Finney, Kirk's shirt is torn, exposing his right shoulder and arm. As Kirk (the stunt double) goes for the knock out blow, the shirt is only a little torn in the front. Then the close up on Kirk catching Finney, his shoulder is exposed again.
Continuity mistake: During Kirk and Lt. Shaw's conversation where Kirk learns that Shaw will be the prosecuting attorney, they are sitting at a table. A shot from behind Shaw's left shoulder shows her turning her head toward Kirk. The scene then shifts to a close-up front shot of Shaw, where she again turns her head.
The Return of the Archons - S1-E22
Continuity mistake: After Kirk and the landing party beam down, they are met by a man who tells them where they can stay for the night but they will have to hurry because it's almost the "red hour." At that time the camera shows a clock that reads 5:58. After being introduced to the daughter of the man who can give them shelter, a gong rings and magically it is 6:00, 2 minutes later, although only 32 seconds of real time has passed. (00:05:18 - 00:05:50)
The Return of the Archons - S1-E22
Continuity mistake: In the exterior shot, the double front doors of Reger's house have large curtained windows in them. After the Enterprise landing party rushes inside and closes the doors, however, they're suddenly solid wood with no windows. (00:06:35)
The Return of the Archons - S1-E22
Continuity mistake: After the Law Giver kills Tamar, he starts to raise his staff. When the camera is in a close up on the Law Giver a second later, it's straight out again. (00:13:15)
The Return of the Archons - S1-E22
Continuity mistake: As Captain Kirk talks to Dr. McCoy, the background changes from stone to a red background in a closeup of Kirk's face. (00:27:05)
The Return of the Archons - S1-E22
Continuity mistake: The lawgivers' robes that Kirk and Spock take off and drop on the floor just inside the doorway disappear after they phaser the wall to reveal Landru. The robes reappear a few minutes later, but have now migrated several feet to one side, bunched up against the wall where they are no longer in tripping range of the actors about to enter the scene. (00:42:25 - 00:45:00)
The Return of the Archons - S1-E22
Continuity mistake: The U.S.S. Archon wasn't violating the prime directive, the prime directive was formed in 2253.
The Return of the Archons - S1-E22
Continuity mistake: As Marpon talks to Spock, his right hand goes from being palm forward toward Spock, to being vertical, palm open, thumb upwards, and back.
The Return of the Archons - S1-E22
Continuity mistake: As Kirk talks to an "absorbed" McCoy, in the back-and-forth cuts between them, the part in Kirk's hair jumps from left to right and back.
The Return of the Archons - S1-E22
Continuity mistake: While Kirk is attempting to convince Marplon and Reger to take them to Landru, a distant shot shows Marplon's right hand descend from his chest to his side. Immediately thereafter, a close-up shows Marplon's hand again suddenly at his chest.
Space Seed - S1-E23
Continuity mistake: When the landing party beams over at the beginning, the transporting officer is wearing a blue jumpsuit, but when they go to the closeup of his hands, they have a red uniform, two braid stripes, and are the standard shot they use when Scotty does the transporting. (00:05:05)
Space Seed - S1-E23
Continuity mistake: At the hearing in the final scene, there are two bits of debris of some sort (small, black and roundish) littering the floor at the bottom left of the screen. Whatever it was disappears when Scott, Spock, Kirk and McCoy get up to leave the room. (00:48:20)
Answer: Kirk was getting his physical and Dr. McCoy probably turned off communications, because if he hadn't, Kirk would have left and headed straight for the bridge, leaving McCoy irritated.